Nerve Guidance by a Decellularized Fibroblast Extracellular Matrix

Abstract

Spinal cord and peripheral nerve injuries require the regeneration of nerve fibers across the lesion site for successful recovery. Providing guidance cues and soluble factors to promote neurite outgrowth and cell survival can enhance repair. The extracellular matrix (ECM) plays a key role in tissue repair by controlling cell adhesion, motility, and growth. In this study, we explored the ability of a mesenchymal ECM to support neurite outgrowth from neurons in the superior cervical ganglia (SCG). Length and morphology of neurites extended on a decellularized fibroblast ECM were compared to those on substrates coated with laminin, a major ECM protein in neural tissue, or fibronectin, the main component of a mesenchymal ECM. Average radial neurite extension was equivalent on laminin and on the decellularized ECM, but contrasted with the shorter, curved neurites observed on the fibronectin substrate. Differences between neurites on fibronectin and on other substrates were confirmed by fast Fourier transform analyses. To control the direction of neurite outgrowth, we developed an ECM with linearly aligned fibril organization by orienting the fibroblasts that deposit the matrix on a polymeric surface micropatterned with a striped chemical interface. Neurites projected from SCGs appeared to reorient in the direction of the pattern. These results highlight the ability of a mesenchymal ECM to enhance neurite extension and to control the directional outgrowth of neurites. This micropatterned decellularized ECM architecture has potential as a regenerative microenvironment for nerve repair.

Promoting neuronal outgrowth using ridged scaffolds coated with extracellular matrix proteins

“…When neuronal attachment was measured on or in between the ridges, laminin and fibronectin did equally well. The observed enhancement of neuronal outgrowth and guidance associated with laminin is in keeping with several other studies investigating different substrates for neuronal regeneration [6, 13, 35, 38]. ECM proteins or their fragments play an important role in cell adhesion through ligand receptor interactions, and these interactions may be an important component to consider in developing novel biomaterials [39-41].…”

“…This can be due to the different amount of proteins used or absorbed into the scaffold. Previous studies have demonstrated concentration dependent differences in cell attachment and outgrowth, however, concentrations used in this study were within range of those used in other studies [6, 24, 36, 37]. It is also interesting to note that the DRG outgrowth rate on the fibronectin coated sheets was still increasing at the 24-48 hour time point and may have results in greater outgrowth length at a later time point.…”

“…Hydrogels may suffer from low cell attachment due to the hydrated surface layer [33]. This issue could be addressed by coating the hydrogel sheets with collagen, laminin, or fibronectin, all of which are classically established as ECM coatings used to promote neurite outgrowth [6, 13, 34, 35]. The current study shows that DRG explants cultured on laminin coated OPF+ sheets had longer neurite outgrowth than fibronectin or collagen coated sheets.…”

“…Control sheets received no additional ECM protein coating other than that which would be present in the serum of the media (referred to as serum coated). The fibronectin was purified by gelatin-Sepharose affinity chromatography from frozen rat plasma [6]. The sheets were then washed 3 times to remove unabsorbed ECM proteins.…”

Processed Tissue–Derived Extracellular Matrices: Tailored Platforms Empowering Diverse Therapeutic Applications

“…The damaged nervous system has a limited regenerative capacity and therefore poses a considerable therapeutic challenge with no effective treatment available. The limited regeneration is though mainly attributed to the inability to recreate the ECM microenvironment within the disrupted neural tissue in order to induce proper neural differentiation and growth . Therefore, a growing body of work describes the use of decellularized tissues as a novel strategy for nerve regeneration.…”